In a luminescent display such as a Field Emission Display (FED), as shown in FIG. 1, electrons 8 from a plurality of emitters 6 in a cathode 7 strike phosphor 3 on the anode plate 4 and cause photon emission. The brightness of the image that results can be greatly enhanced by applying a thin, aluminum film on the cathode side of the phosphor. Such films are commonly used in CRTs. In CRTs, there is a significant space between the cathode and the anode usually exceeding 25 cm. However, in the case of an FED, the cathode-anode separation is roughly 1-2 mm and the aluminum film will be held at an electrical potential of roughly 5-10 kV relative to the cathode, and as such, arcing may occur across the gap. For a given configuration, the energy of the arc will depend on the size of the aluminum sheet. If the aluminum is applied over the entire anode screen (as it is in CRTs), the arc may be large enough to cause considerable damage to the cathode. This invention involves segmenting the aluminum sheet so as to minimize the capacitance of any individual strip and limit the arc energy.
As shown in FIG. 1, a current practice in FED technology is to apply a transparent conductor 1 (e.g. indium tin oxide) to the glass substrate 2 of the anode 4. Phosphor lines 3 are applied over the transparent conductor 1. The anode potential 5 is then applied to this conductor 1. To emit electrons from particular array emitter apertures 25, a gate potential Vq is applied to specific gates 26 which may be supported on some dielectric material 28. The dielectric material 28 and electron emitters 6 can be supported on a cathode assembly 31 which can be supported on a cathode back plate 29, which in turn is supported on back plate support structure 30.
Experience with CRTs has shown that using an aluminum film on the cathode side of the phosphor greatly enhances the brightness of the displayed image. Unfortunately, since the cathode and anode of a luminescent display such as an FED are so closely spaced (1-2 mm) and roughly 5-10 kV is applied between them, arcing may occur and damage to the cathode/gate structure may result. Therefore, those skilled in the art have avoided conductive layers on the phosphor elements.